Automotive ignition booster system with automatic starting control



y 1939- E. A. MCMURTRY 2,158,634

AUTOMOTIVE IGNITION BOOSTER SYSTEM WITH AUTOMATIC STARTING CONTROL Filed Aug. 20, 1937 IHVE-HTOR Patented May 16, 1939 PATENT OFFICE AUTOMOTIVE IGNITION BOOSTER SYSTEM WITH AUTOMATIC STARTING CONTROL Edward, A. McMurtry, Chicago, 111.

Application August 20, 1937,. Serial No. 160,020

3 Claims.

My invention relates to ignition systems for internal combustion engines and the object and purpose of my invention is to provide an ideal ignition-system that will deliver a hotter and stronger spark at the spark plugs during the starting operation, than the normal running spark, and automatic control means whereby the normal running spark intensity is restored the moment the engine starts, and maintained during the period of engine operation.

A further purpose of my invention is to provide such an-ignition system without the use of auxiliary batteries or cells to effect the required ignition current boost or increase, because they involve regular care and replacement and become in themselves the source of much trouble and failure.

A further purpose of my invention is to provide an ignition system having all of the above mentioned ideal qualities but involving only the most simple circuits and elements with little or nothing to get out of order or require attention during the lifetime of the car in which it is installed.

An additional purpose of my invention is to provide such quick and easy starting of the engine that the starting drain on the storage battery is very greatly reduced so that more reserve battery power is available for radio, cigar lighter, windshield defroster etc., and the life of the battery, thus relieved of the major strain of prolonged starter operation, will be increased greatly beyond the usual period of service.

I deem it advisable to state that up to the present time the starting of an automobile engine has involved the usual connection of the electric starting motor across the storage battery terminals, causing a very heavy drain on the battery and consequently a considerable drop in voltage across the battery terminals. As a result, the voltage supplied to the ignition system which is also connected across the same battery terminals, is correspondingly lowered during the period that the starting motor is in operation and consequently the spark at the spark plugs is proportionally weaker and thinner than the normal running spark. Under these conditions if the carburetor is slightly flooded or the mixture delivered to the cylinders slightly richer or leaner than a certain critical value the starting motor will have to operate for a considerable period of time before the engine will fire on the greatly weakened spark, resulting in appreciable discharge of the battery with the attendant wear and tear on the plates.

If the battery is not up to full charge or not in good condition, or the engine and battery are very cold as in severe winter weather with the oil in the engine greatly stiffened, the current flowing in the ignition system will be so greatly reduced during the operation'of the starting motor that little or no spark will be produced. at the spark plugs and the raw cold mixture will not be ignited with the result that the engine will fail to start. Even when the mixture is pre-heated before entering the chilled cylinders in winter starting, the vapor instantly condenses on the cold cylinder walls and the weakened starting spark cannot ignite the heavy, recondensed charge of vapor.

I have found that with the hotter and stronger starting spark which my ideal ignition system provides, the engine will fire and start almost instantly under such conditions as those mentioned above, and that this hotter starting spark in the engine cylinder itself is more vital to quick starting than all other elements combined.

I achieve the purposes and objects of my invention by means of the circuit and mechanism shown in the drawing and described in the following paragraphs,-

Referring to the drawing, I have shown the ordinary automotive starting and primary ignition circuits comprising storage battery I, having the negative terminal 2 grounded on the automobile frame as represented by G, and the positive terminal 3 connected to the stationary contact 5 of the starting switch.

Stationary contact 4 of the starting switch is connected to terminal 23 of the starting motor 25, and motor terminal 20 is grounded at G. Bridging contact member 6 of the starting switch is attached to shaft 1 which carries button 8 at its extremity so that when 8 is depressed, member 6 will connect contacts 4 and 5 of the starting switch thereby actuating the starting motor in the regular way. The high tension ignition coil is represented at 20 and only the primary winding 2| is shown having terminals M and 15. The high tension terminal is indicated at 22. The ammeter A, ignition switch [5, the ignition coil primary 2| and the make and break contacts I] and I8 of the distributor are all connected in series between the positive terminal 3 of the battery and the distributor ground G, all in the usual way. However, I place the regular primary current limiting resistor I3 as shown, also in series connection, but it must be located between coil terminal l4 and battery terminal 3. This resistor might be placed in series connection between the ammeter A and the ignition switch I6 if desired.

Now, I provide wire l2, one end of which is connected to terminal I4 of the coil primary 2!, and the other end of this wire terminates in a terminal H. Flexible conductor l has one of its ends connected to terminal H and its other end soldered, Welded or otherwise electrically connected at point 9 to bridging contact member 6 as shown.

When the ignition switch is closed and the starting switch is actuated by pressure on button 8, bridging member 6 closes contacts 4 and 5. It is evident that terminal M of the coil through conductors l2, I0 and member 6, is connected directly to contact and so we observe that ammeter A, ignition switch l6 and resistor l3 are temporarily short circuited. This allows a greatly increased amount of current to flow in the primary 2| as long as the starting switch is actuated. The result is a greatly increased output from the high tension coil and a very hot and fat spark at the spark plugs with rapid or instantaneous starting of the engine.

The moment the engine starts and the starting switch is released, bridging contact 6 is withdrawn from connection with contacts 4 and 5 and the connection between coil terminal l4 and switch contact 5 is broken, the ignition current must now travel through ammeter A, ignition switch I6 and resistor l3 before it reaches terminal M. The ignition system will now function on the normal current which is determined by the value of the standard resistor 13 as long as the engine continues to run. It is evident that every time the starting switch is actuated, the output of the ignition system is greatly increased while the starting switch is depressed, and only during this period, after which normal output is automatically restored.

My invention involves practically no additional mechanism or expense in its addition to a car, and once installed, there is nothing to get out of order during the lifetime of the car or to require any adjustment or attention.

In the following claims the term battery terminal of the ignition coil" refers to that primary terminal of the coil which is connected to the battery side of the primary circuit, and is represented as terminal I4 in the drawing.

I claim broadly,

1. In combination, an ignition system for internal combustion engines including a high tension coil, a storage battery, a current limiting resistor connected in the primary circuit of said system between said coil and said battery, an electric self starting mechanism adapted to be energized by said battery, said mechanism including a starting switch comprising stationary contacts and a bridging contact member, and an electrical conductor forming a connection between said bridging contact member and the battery terminal of said coil.

2. In combination with an ignition system for an internal combustion engine including a high tension coil, and an electric self starting device including a starting switch having a bridging contact member, of an electrical conductor having one terminal thereof in electrical contact with said bridging contact member and the other terminal connected to one of the primary terminals of said high tension coil.

3. In combination, an ignition system for internal combustion engines including an induction coil and a current limiting resistor, an electric self starter including a starting switch, a source of current supply common to both said ignition system and said self starter, and an electrical conductor establishing an electrical connection between the bridging contact of said starting switch and a primary terminal of said induction coil.

EDWARD A. MCMURTRY. 

